Oil well drilling turbine screen



P. 8 ml. w. a w

G. P. WAGNER OIL WELL DRILLING TURBINE SCREEN ASSEMBLY Filed Nov. 22,1.949.

Feb. 21,1956

United States Patent 011. WELL DRILLING TURBINE SCREEN ASSEMBLY GeorgeP. Wagner, Mount Vernon, N. Y., assignor to The Engineering DevelopmentCompany, Incorporated, a corporation of Texas Application November 22,1949, Serial No. 128,844

8 Claims. (Cl. 25332) The invention relates to oil well drillingturbines, and more particularly to a screen assembly for such turbines.

In an oil well drilling turbine, the turbine is located at the bottom ofthe drill stem and is operated by drilling mud pumped downwardly throughthe drill stem. The drilling operation grinds off pieces of rock whichare carried upwardly by the drilling mud on the outside of the stem. Themud is used over and over. Despite all efforts to settle out all theparticles and grit which are carried upwardly, some of these almostinevitably get through with the circulated mud and pass back downwardly. If a sufiicient quantity of these particles accumulates in theturbine, there will be a grinding action which will wear out the turbineblades and also a tendency for this material to get into the bearingsand wear out the bearings.

In addition, whenever pumping is stopped, there is likely to be abackward surge of drilling mud from the bottom of the well into theturbine, carrying with it particles of suflicient size to cause damageto the turbine blades if they get into the driving section of theturbine.

The primary object of the present invention is to provide an arrangementfor avoiding damage to the turbine blades and to the bearings, whichmight be caused by such particles.

A further object of the invention is to provide an arrangement of thisnature which is simple in construction, sturdy and durable.

Still another object of the invention is to provide, in an arrangementof this type, an easily replaceable screen within the turbine.

A further object of the invention is to provide a turbine arrangement inwhich any accumulation of such particles within the turbine can bereadily eliminated without disassembling the turbine.

In general, the invention contemplates the provision, in an oil welldrilling turbine having the shaft, cooperating stator and rotor bladesbetween the shaft and the casing, and a bore in the lower end of theshaft with openings into the casing, of a space within the casing aroundthe shaft between the blade section and the lower bearing, above whichbearing are located the openings into the bore. Within an intermediatepart of this space is arranged a screen. The openings into the shaftbore communicate with the space below the screen, and a plug opening isprovided into the space above the screen through the casing wall.

The screen according to the invention is formed by concentric lengthssecurely held within the casing in spaced relation to each other and tothe shaft.

Further objects and advantages of the invention will appear more fullyfrom the following description, especially when taken in conjunctionwith the accompanying drawings which form a part thereof.

In the drawings:

Fig. l is a cross-section through a portion of a turbine operating oilwell drill embodying my invention;

Fig. 2 is a cross-section on the line 22 of Fig. l;

Fig. 3 is a side elevation, .partly in section on the line 33 of Fig. 2,of the upper portion of the screen ring;

Fig. 4 is a detail view of the fluidjnlet and outlet; and

Fig. 5 is a top plan view on :a larger scale of the screen or strainer.

The invention is applicable to an oil well drilling turbine of the typeshown -in my prior .application S. N. 729,613, filed February 17.,1947., now Patent No. 2,646,962. In that application, there is describeda tinbine arrangement in which the shaft, to which the bit is to beattached is arranged within a casing formed of a sleeve made up of aplurality of separate parts and a unitary outer cover surrounding thissleeve and slidable thereover.

in the arrangement shown herein, there is a cover or outer casing member2 which extends substantially the length of the turbine drilling unit.Within this is a sleeve formed of a plurality of sections. These includea bearing section 4, a strainer or screen section made up of parts 6, 8,16 and a turbine section made up of parts 12, 14, 16, etc. Within thissleeve turns a shaft having a smaller portion 18 and a larger portion 20at its lower end, and having a lower extension 22. threaded to receive adrill'bit.

Keyed on shaft section 18, or otherwise secured thereto so as not torotate with respect to it, are a plurality of rotor rings 24 having-blades 26. These rings are interlocked, .in the manner shown in theapplication referred to above, by projections 28 on each ring fittinginto notches .in the succeeding ring. At the bottom of this turbineblade section is a ring 30 which at its lower end has a reduced portion32, forming with the enlargement 20 of the shaft a-notch for receiving aprojection to be described below.

The stator rings 12, 14, '16 have stator blades 34. It will be notedthat the stator and rotor blades are arranged alternately along thelength 'of the unit, or in other Words that the stator blades are spacedand the rotor blades located in the places between the stator blades.The stator rings also have projections 36 each engaging in notches inthe nearest succeeding ring, these projections and notches being similarto those described below in connection with the strainer sleeve part.

The sleeve part 10 has a projection 38 engaging in the notch 32. Thisserves to prevent relative longitudinal movement between the shaft andthe sleeve. Part 10 is also interlocked with the lowest stator ring 12.

Part 10 is interlocked with part 8 which is the strainer part. This isshown in more detail in Figs. 2, 3 and 5. Part 8 includes acomparatively thick'ring section which is of the same thickness assleeve parts 6 and 10. Within this ring section are two thin ringsections 49 and 42, spaced from each other and from the ring section 8,and likewise spaced from the shaft section 20. These parts are heldtogether at each end by blocks 44 which are set into notches in the endsof the ring sections 8, 40 and 42. The blocks .are secured to the ringsections by welding as indicated at 46. Thus the various rings are heldin assembled, spaced relation with one another.

The ends of the outer ring 8 have peripherally spaced axiallly extendingprojections 48 leaving between them notches 50. The sleeve section 10has mating projections 52. engaging in these notches. It will be notedthat the sides 54 of the notches and projections are radial to the axisof the shaft. The result is that, when the two parts are assembledtogether, not .only is relative rotary movement between the partsprevented but also radial movement. Thus when any two sleeve parts areassembled together their outer vsurfaces are continuously aligned withone another.

Sleeve part 6 is similarly interlocked with sleeve part 8, and bearingpart 4 is interlocked with part 6. Bearing part 4 is also keyed to theouter casing 2 as at 56. The

bearing part includes a bearing portion 58,. this being for example abronze bearing sleeve which engages the shaft to support it axiallywithin the sleeve, and packings 60. The parts of the bearing may be heldwithin the sleeve in any suitable way, as by nuts 62 threaded in thelower end of the sleeve.

The whole sleeve formed of these sleeve sections is held within theouter casing 2 by a nut 64 threaded in the lower end of the outer casing2.

The shaft 29 has av bore 66 therein opening at the lower end, and holes68 communicating with this bore. There may be two or more holes in eachset, and several sets may be spaced along the shaft if desired. Theholes, however, are located above the upper packing member 60 and belowthe strainer sleeve section 8, and opposite sleeve part 6. Sleeve part10 and the outer casing have aligned holes therethrough which may beclosed by threaded plugs 70.

It will be seen that the arrangement thus provides a space between thesleeve and the shaft, this space having the screen 8 at an intermediatepoint, having the openings and plugs 70 above the screen and having theholes 68 below the screen. This space is located between the turbineformed by blades 26, 34 and bearing 58 which closes off the spacebetween the casing and the shaft at its lower end.

With such an arrangement, it is possibleto overcome one of the greatdifliculties encountered in the drilling of the oil well by a turbine.No matter what care is exercised, a certain amount of rock in pieces ofmoderate size is bound to be pumped along with the oil well pumpingfluid. In addition, whenever the operation of the pumps is stopped thereis a tendency for the fluid in the bottom of the well to flow in areverse direction upwardly through the bore of the shaft and into theturbine. It is of course possible to eliminate a certain portion of thismaterial by the use of suitable screens. However, a certain amount of itis bound to get to the drilling tool. The present invention makes itpossible to eliminate this collected material without the necessity ofdis assembling the turbine unit. Whenever the turbine is lifted from theWell, the plug 70 is removed and fluid is circulated by a pump upthrough bore 66, the top of the turbine being shut up. This will resultin washing out any particles collected above the screen 8 through thehole provided by removal of plug 70. It now fluid is introduced at plug70 and allowed to flow down through the screen and through holes 68 andbore 66, any material collected below the screen 8 will likewise beremoved. It is therefore possible to eliminate these particles, whichotherwise might result in serious damage to the blades and the bearings,at periodic intervals without taking the turbine apart.

While I have described herein one embodiment of my invention, I wish itto be understood that I do not intend to limit myself thereby exceptwithin the scope of the claims hereto or hereinafter appended.

I claim:

1. In an oil well drilling turbine, a casing, a shaft mounted to turn inthe casing, said shaft having a bore therein, cooperating turbine bladeson said shaft and easing, said shaft and easing having a spacetherebetween on one side of said turbine blades, means between thecasing and shaft closing the end of said space remote from the turbineblades, a screen in an intermediate part of said space, said shafthaving an opening therein connecting the part of the space on the sideof the screen remote from the turbine blades to the bore, said casinghaving an opening therethrough into the part of the space on the side ofsaid screen nearest the turbine blades, and removable means for closingsaid last opening.

2. In a device as claimed in claim 1, said space closing meanscomprising a bearing for said shaft.

3. In a device as claimed in claim 1, said screen comprising a pluralityof spaced concentric rings.

4. In an oil well drilling turbine, a casing composed ofan inner sleeveand an outer cover concentric therewith, said sleeve being formed of aplurality of sections, means interlocking successive sections againstrotation with respect to one another, means operatively engaging thecover and at least one of said sections to lock said section againstrotation with respect to the cover, said sleeve sections including, fromone end to the other, a stator section having inwardly directed spacedstator blades, a screen section and a bearing section, a shaft withinsaid sleeve section concentric therewith, said screen section beingradially spaced from the shaft and said bearing section including abearing engaging the shaft, a screen carried by an intermediate part ofthe screen section extending between the sleeve screen section and theshaft, said shaft having rotor blades secured thereon in the spacesbetween the stator blades, said shaft having a bore therein opening onthe side of said bearing remote from the first end of the sleeve sectionand being provided with a hole communicating with said bore and openingopposite the screen section on the side of the screen remote from thefirst end of the sleeve section, said screen section and cover havingaligned openings therethrough in the part of the screen section on theside of the screen nearest the first end of the sleeve section, and

removable means for closing said openings.

5. In a device as claimed in claim 4, said screen including at least onering secured to the screen section and radially spaced from the screensection and the shaft.

6. In a device as claimed in claim 5, a packing at the side of thebearing near the first end of the sleeve section extending between thebearing section and the shaft, so as to provide a sealing structurebetween the bearing and the shaft, said hole being located immediatelyadjacent said packing on the side thereof nearest the first end of thesleeve section.

7. In a device as claimed in claim 4-, a packing at the side of thebearing near the first end of the sleeve section extending between thebearing section and the shaft, so as to provide a sealing structurebetween the bearing and the shaft, said hole being located immediatelyadjacent said packing on the side thereof nearest the first end of thesleeve section.

8. In an oil well drilling turbine, a casing, a shaft mounted to turn inthe casing, said shaft having a bore therein, cooperating turbine bladeson said shaft and easing, said shaft and casing having a spacetherebetween on one side of said turbine blades, means between thecasing and shaft closing the end of said space remote from the turbineblades, and a screen in an intermediate part of said space and occupyingall of such part of the space between the casing and the shaft, saidshaft having an opening therein connecting the part of the space on theside of the screen remote from the turbine blades to the bore, saidscreen terminating short of each end of the space and comprising aplurality of. spaced concentric rings, the spaces between the ringsbeing open at each end of the screen.

References Cited in the file of this patent UNITED STATES PATENTS400,209 Haskins Mar. 26, 1889 2,044,349 Dichl June l6, 1936 2,178,003Smellie Oct. 31, 1939 2,353,534 Yost July ll, 1944 2,498,913 ClaytonFeb. 28, 1950

1. IN AN OIL WELL DRILLING TURBINE, A CASING, A SHAFT MOUTED TO TURN INTHE CASING, SAID SHAFT HAVING A BORE THEREIN, COOPERATING TURBINE BLADESON SAID SHAFT AND CASING, SAID SHAFT AND CASING HAVING A SPACETHEREBETWEEN ON ONE SIDE OF SAID TURBINE BLADES, MEANS BETWEEN THECASING AND SHAFT CLOSING THE END OF SAID SPACE REMOTE FROM THE TURBINEBLADES, A SCREEN IN AN INTERMEDIATE PART OF SAID SPACE, SAID SHAFTHAVING AN OPENING THEREIN CONNECTING THE PART OF THE SPACE ON THE SIDEOF THE SCREEN REMOTE FROM THE TURBINE BLADES TO THE BORE, SAID CASINGHAVING AN OPENING THERETHROUGH INTO THE PART OF THE SPACE ON THE SIDE OFSAID SCREEN NEAREST THE TURBINE BLADES, AND REMOVABLE MEANS FOR CLOSINGSAID LAST OPENING.